The present invention relates to internal combustion engines and in particular to reducing the temperature of fuel and air provided to the engines to improve performance.
Many modern vehicles have small displacement supercharged or turbo charged engines to improve mileage, or moderate to large displacement supercharged or turbo charged engines to improve performance. An unavoidable consequence of supercharging or turbo charging is an increase in intake air temperature. The increased air temperature may cause detonation (e.g., pre-ignition or pinging) under acceleration when the fuel air mixture is ignited prematurely, and limits the amount of boost (increased air pressure) which may be used. Uncontrolled detonation may damage or destroy the engine.
Heat enchanters, commonly referred to as intercoolers, are often added to supercharged or turbo charged engines between the supercharger or turbo charger and the engine to at least somewhat cool the intake air. These intercoolers maybe air to air, or air to coolant. The air to coolant intercoolers require a second coolant to air heat exchanger in an ambient air stream to cool the coolant. Unfortunately, it is often difficult to obtain the desired amount of cooling with known intercoolers, thus limiting potential of the supercharger of turbo charger to increase performance.
Additionally, detonation may be reduced by cooling the liquid fuel provided to the engine, having a similar effect as cooling the intake air. Common methods for cooling liquid fuel include containers filled with ice and coiled fuel lines passing through the containers. Unfortunately, the fuel may be immediately heated upon leaving the container, and the ice melts quickly, making this approach only useful for a very brief period of time.
U.S. Pat. No. 6,269,804 discloses fuel rails having a coolant line running therethrough. Unfortunately, the fuel is exposed to the fuel rail housing, and presence of the coolant line provides very little reduction in fuel temperature.